Messages in this thread | | | Date | Fri, 17 Mar 2006 00:52:08 +0200 | From | "Yitzchak Eidus" <> | Subject | Re: puting task to TASK_INTERRUPTIBLE before adding it to an wait queue |
| |
On 3/17/06, Yitzchak Eidus <ieidus@gmail.com> wrote: > the function worker_thread in kernel 2.6.15.6 first put the task to > TASK_INTERRUPTIBLE and only then add itself to an wait queue: > set_current_state(TASK_INTERRUPTIBLE); > while (!kthread_should_stop()) { > add_wait_queue(&cwq->more_work, &wait); > .... > my question is, what will happen if the timeslice for the > worker_thread will finished just before it add itself to the wait > queue? > wont it call schedule() that will find the task is in > TASK_INTERRUPTIBLE state and remove it from the runqueue? ( that what > schedule() should do no? ) > and then how will the kernel be able to call to worker_thread ever if > it isnt in any list??? > thanks for the comments! >
more over the whole loop look like that: set_current_state(TASK_INTERRUPTIBLE); while (!kthread_should_stop()) { add_wait_queue(&cwq->more_work, &wait); if (list_empty(&cwq->worklist)) schedule(); else __set_current_state(TASK_RUNNING); remove_wait_queue(&cwq->more_work, &wait);
if (!list_empty(&cwq->worklist)) run_workqueue(cwq); set_current_state(TASK_INTERRUPTIBLE); }
what was the logic of putting the set_current_state(TASK_INTERRUPTIBLE); before the loop and in the last statement of the loop?
why not use something like this: while (!kthread_should_stop()) { add_wait_queue(&cwq->more_work, &wait); set_current_state(TASK_INTERRUPTIBLE); if (list_empty(&cwq->worklist)) schedule(); else __set_current_state(TASK_RUNNING); remove_wait_queue(&cwq->more_work, &wait);
if (!list_empty(&cwq->worklist)) run_workqueue(cwq); } that do the same thing without putting the task before the loop and in the loop...? ( unless i am missing something? ) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |